IO6 MANUAL OF BACTERIOLOGY. 



withdrawn inoculate the tubes; also make cover-glass prep- 

 arations. In the same manner inoculate tubes and make 

 cover-glass preparations from the spleen, the kidneys, the 

 pleural cavity, the pericardial cavity, the lungs, and the 

 blood inside the heart. All incisions are to be made through 

 the burned surfaces, and all material collected for inocula- 

 tion is to be obtained through burned surfaces. In steriliz- 

 ing the instruments in the flame avoid sputtering, especially 

 when they become covered with oil from adipose tissue. 

 Pieces of lung, liver, spleen, kidney and other organs, as 

 may be indicated, should be placed in 95 per cent, alcohol 

 for fixation and hardening. The animal and the board on 

 which it was extended should be covered with bichloride 

 of mercury solution i-iooo, and afterwards burned. The 

 cage or jar and the instruments, dishes and towels used 

 should be sterilized by steam. The hands of the operator 

 should be washed thoroughly with soap and water and with 

 a i-iooo solution of bichloride of mercury. 



FIG. 36. 



Method of Making Collodion Capsules. (After McCrae.) 



Collodion Capsules. Bacteria may be cultivated in the 

 living body of an animal, without infecting the animal, 

 when they are enclosed in collodion capsules. Their soluble 

 products are able to diffuse through the collodion, while the 

 animal's fluid may pass into the sac to nourish them. These 

 capsules were originally made by dipping the round end of 

 a glass rod into collodion repeatedly. McCrae's method 1 

 is easier and more satisfactory. (Fig. 36.) 



A piece of glass tubing is taken, and a narrow neck drawn on it near 

 one end. This end of the tube is rounded in the flame, and the body 



'Journal of Experimental Medicine, Vol. V., p. 635. 



